A liquid crystal display device is the most important display device recently used in a multimedia society, and is widely used in a mobile phone, a monitor for a computer, a notebook computer, and a television. The liquid crystal display device has a TN mode, in which a liquid crystal layer, in which nematic liquid crystals are arranged in a twist form, is interposed between two orthogonal polarizing plates, and then an electric field is applied in a direction vertical to a substrate. In the TN mode scheme, since the liquid crystals are aligned in the direction vertical to the substrate when a black color is displayed, double refraction and light leakage are incurred by liquid crystal molecules at an inclined viewing angle.
In order to solve the viewing angle problem in the TN mode scheme, an in-plane switching (IPS) mode, in which two electrodes are formed on one substrate, and a director of the liquid crystal is controlled with a lateral electric field generated between the two electrodes, has been introduced. That is, the IPS mode scheme is also referred to as an in-plane switching liquid crystal display or a horizontal electric field type liquid crystal display, and an electrode is disposed on the same plane within a cell, in which the liquid crystal is disposed, so that the liquid crystals are not aligned in a vertical direction, but are aligned to be parallel to a horizontal surface of the electrode.
However, in the case of the IPS mode scheme, it may be difficult to implement a high quality image by high light reflectance of a pixel electrode and a common electrode.